This invention relates to a brush bristle unit for use mainly as a replacement for present units used on a certain type of rotary brush roll provided on airport runway sweepers. These sweepers have a drum and angularly spaced around the drum are longitudinally-extending receiving and retaining channels which receive and retain the brush units. Each of these prior art brush units consists of fiber bristles mounted by complicated means on a longitudinally-extending retaining strip and extending radially therefrom. There is a need to provide some simple means for replacing these fiber brush bristle units with more durable plastic bristle units and the present invention makes this economically feasible.